My guess is you have a bad Logic Board which seems to be quite common with these 2019 models, especially the 16" model. The EtreCheck report shows the Bluetooth daemon has crashed 98 times. Plus there are dozens of the "ProxiedDevice-Bridge" crash reports which also seem to be common as well for those posting issues with their 2019 laptops. I don't see anything third party software that is known to cause problems with macOS.
You can try an SMC Reset (read the instructions since the process has changed for the 2018-2020 models) and a PRAM Reset (hold the PRAM Reset for two chimes if possible, not always possible for the 2018-2020 models).
Try running the Apple Diagnostics by connecting over WiFi. If you cannot authenticate with your WiFi network, then it confirms you have a hardware issue since no OS is involved at that point.
You can try a firmware "Revive" to see if that makes any difference (doubtful). The "Revive" will reset both the T2 security chip & system firmware.
If you have never had the Top Case Assembly replaced for a keyboard, trackpad, touchbar, or battery replacement, then that is another repair cost you will need to consider at some depending on the age of the laptop since batteries tend to need replaced sometime between 3 - 5 years old which can be expensive ($250 US or maybe even more depending on how the AASP performs the repair). Just something to consider when getting a laptop repaired.
I think you will need to have the Logic Board replaced on this laptop to resolve your current WiFi & Bluetooth issues which is an expensive repair (easily $600+ US).
Before you do anything, make sure to have a good backup while you can. A firmware "Revive" should not cause data loss, but if the process cannot complete because of a hardware issue, then it could leave the laptop in a completely unusable state where you won't even be able to access the data stored on the internal SSD.
People should always have frequent and regular backups of their computer and all external media (including the cloud) which contains important & unique data. There are a lot more new ways to lose all access to the data stored on the internal SSD of these newer Macs because of new hardware & software security features.
